Method of and machine for producing gears



E. WILDHABER METHOD OF AND MACHINE FOR RRODUCING GEARS July1 o,192s. 1,676,371

- Filed. May 23, 1927 4 Sheets-Sheet 1 INVENTOR v mmzdimm Jul 10, 1928.

. 1,676,371 E. WILDHABER F AND MACHINE FOR PRODUCING GEARS Filed May 25, 1927 '4 Sheets-Sheet 2 INVENTOR Q'zwst Widlzafie July 10, 1928. 1,676,371

' E. WILDHABER v METHOD OF AND MACHINE FOR PRODUCING GEARS Filed May 25, 1927 4 Sheets-Sheet 3 l L 32 2 I sa L \55 I 0 /aa as a7 a4 87 F14 15 I INVENTOR Efmst ATTORNIQj Patented July 10, 1928.

UNITED STATES PATENT OFFICE.

ERNEST WILDHABER, OF BROOKLYN, NEW YORK, ASSIGNOR TO GLEASON WORKS, OI

ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

METHOD or AND MACHINE son rnonncrneonaas.

Application filed May 23, 1927, Serial No. 193,611, and in Great Britain and France June 14, 1826.

The present invention relates to gears and particularly to a method and machine for producing longitudinally curved tooth hypoid gears.

It has been proposed, heretofore, to produce hypoid gears by cutting the larger member of the pair in a forming or non-gencrating process and generating the other member in an operation in which the tool and blank are rolled relatively to each other in the manner of a gear meshing with the non-generated member. Gear cutting experience indicates generally, however, that gear pairs produced in a generating or rolling process have a smoother tooth surface finish and will mesh together more quietly than gear pairs where one or both members are non-generated.

The primary object of this invention is to provide a method and apparatus for producing longitudinally curved tooth hypold gears, of such character that both members of a pair of such gears may be generated.

A further object of this invention is to provide a generating method for gears of the character described, which will be theoretically correct. To'this end, gears are generated, according to the present invention, conjugate to basic helicoidal segments, which have the same relation to a system of hypoid gears, as have the rack and crown gear-to spur and bevel gears, respectively Other'objects of the invention will appear hereinafter from the specification and from the recital of the appended claims. In the drawings: Figures 1 and 2 are a plan view and a side elevation, respectively, of a pair of gears produced according to this invention;

- Figures 3 and 4 are a side elevation'and plan view, respectively, of a helicoidal segment such as forms the basic member for the v asmight be used for the generation of invention;

Figure 5 is a fragmentary view of a pairof complementary helicoidal segments, such generation of a pair gears according to the present ofgears with this invention, in mesh;

Figures 6 and 7 are views illustrating diagrammatically in plan and in .side elevation, respectively, the pitch surfaces-of a pair of gears wlth angularly disposed nonmtersectmg axes; Figures 8 and 9 are a. plan viewand a tion of both members basic helicoidal segment;

Figure 10 is a fragmentary sectional view showing the relation between a pair of tools, such as might be employed in producing a pair of gears according to this Invention;

Figure 11 is a side elevation, partly in section, showing the relation between a pair of grinding wheels such as might be employed in producing a pair of longitudinally curved tooth gears according to one. modification of my invention;

Figure 12 is a diagrammatic view showing the relation between one of said grinding wheels and the basic helicoidal segment it represents; I

Figure 13 is a view illustrating diagrammatically a possible modification of my invention; and

Figures 14 and 15 are a lan viewandside elevation, respectively, 's owing somewhat diagrammatically one embodiment of a machine for producing gears according to this invention.

The present application is a continuation in part of my copending application, Serial No. 38,7 25, filed June 22, 1925. The present application covers specifically the application of the principles set forth in the prior application mentioned, to the production of longitudinally curved tooth hypoid gears.

e purpose of the present invention is to provide a theoretically correct method for generating both members of a pair of Iongitudinally curved tooth hy oid gears. It is elieved that gears produced according to this invention will be .quieter in operatlon and of more satisfactory construction than gears, wherg one member of the pair isnon-generate One difliculty experienced'in the generaof a pair of gears'ar ranged with, axes angularly disposed and non-intersecting has been the inability to secure a theoretically correct basic member from which tofgenerate such gears, regardless of their ratio. In bevel gears and spur gears, a pair of gears will mesh correctly together-with full-line contact when they are capable of meshing with complementary basic members. These b11810 members are racks for spur gear-sand crown gears for I of' the axis about the respective axes 12 and 13 of the cated at 12 and the bevel gears. The present invention has as its basis the provision of a basic member, comparable to the crown gear in bevel gearing and the rack in spur gearing, from which the tooth structure of gears with non-inter secting axes may be derived and from which the proportions of such gears regardless of ratio may be determined. This basic meniber is a helicoidal segment and gears are generated according to this invention by rolling the blank and tool relatively to each other as though the blank were meshing with a basic helicoidal segment represented by the tool. The rolling motion will comprise, preferably, a rotary motion of the blank on its axis, a relative movement between the tool and blank about an axis angularly disposed to and ofiset from, the blank axis, and an additional feeding movementbetween the tool and blank, preferably in the direction about which the last named movement takes place. The blank 'may be intermittently or continuously indexed.

The theory upon which the present invention is based will be described more particularly with reference to the accompany? ing drawings. Figures 1 and 2 show a pair of longitudinallycurved tooth hypoid gears 10 and 11, constructed according to one embodiment of this invention. These gears are so arranged relatively to each other .that their axesare angularly disposed and nonintersecting. The axis of the gear 10 is indiaxis of the pinion 11 at 13. The relative motion of a pairof gears of this type, sidered, at any instance, as a turning motion about an instantaneous axis 14 and a simultaneous translation along said axis 14. The pitch surfaces 15 and, 16 of the gears are hyperboloids of revolution,

movement of the instantaneous axis 14 gears. The pitch surfaces of the gears will contact along the line 14. The teeth 18 of the pinion 11 are preferably disposed out-- 1 side the pinion pitch surface 16, as with this construction it is possible to increase the size of the (pinion overa bevel pinion of a cor-.

respon ing ratio and so give it increased strength. The teeth 17 of the gear 16 will then lie within the gear pitch surface 15.

Besides the gear 11 there exists an infinite number of other gears which may mesh with the gear 10 in such a way that the line 14 is the'instantaneous axis. The pitch hyperboloid's of all these gears will contact with the pitch hyperboloid of the gear 10 aldng the line 14 and at any instant the relative motion of the contacting gears may be considered-as a combined sliding and rolling motion about and in the'direction of the axis 14. In no case will the ratio of relative sliding and turning be gears which 'maymesh wit the gear 10.

,member along the same lines,

as is well known, can' be con-1 being produced the same for the difierent neous axis, but also on the lead or advance per revolution of the instantaneous motion.

A consideration of the above facts has resulted in the conclusion that two hypoid gears, third member and will contact with said if this third member is given not only a rotary motion, butalso a translatory motion in the direction of its axis. This third member will, have a helicoidal pitch surface which contacts with the pitch surfaces of the gears 10 and 11 along the line 14 and the instantaneous relative motion of this third member.

with respect to either gear 10 or 11 is identical with the relative motion between these two gears, as will be more fully explained hereafter. Such a third member maybe made, hence, the basic member for the production of gears with-non-intersecting axes which are theoretically accurate and which mesh with line contact. It follows, therefore, that a hypoid gear may be accurately generated if the tive to the tool as though it were meshing with .a basic helicoidal member represented by the tool. i

A third member of the considered type is illustrated in Figures3 and 4. The teeth 24 of this basic helicoidal segment 25 are longitudinally curved and its tooth surfaces 26 have a constant inclination to. a plane perpendicular to the axis 27 of the segment.

such as' 10 and 11, will mesh with a blank is given amotion rela- The teeth of this member may be of any suitable curvature. Preferably, however, the tooth surfaces 26 are surfaces of revolution such as might be swept out by a cutting.

blade 29 m'ovirlg on the arc of a circle 30.

The relations and formulas which determine the-shape of the basic member, its lead and its position relative to theblank to be operated upon, and which determine, consequently,

7, 31m 32 and 34 These the relative positions of tool and blank and their relative motions for generagears contact along the line 35 which is the instantaneous axis. The angles a and-a," included between the instantaneous axis 35 and the axes 31 and 32 are determined in known manner by the ratio:

lili swhereell' and N are the tooth numbers of relation: 1

When the axes 31'and 32 are at right angles, a+a=90, and sin a"=cosine a and /I 1 tangent a I The above formulas will become:

. p I tan a (1) In terms of C the distance between the axes of the two gears,which distance is equal to z'+z", formula (2) becomes:

a'G sin a or z"=C cos a The pitch hyperboloids 33 and 34 which, as stated, may be considered the pitch surfaces of a. pair of gears, when rotated about their respective axes 31 and 32, in the inverse ratio of the tooth numbers N and N' of the gears, will roll on each other and in addition slide in the direction of their contact line 35. At any instance, the relative motion between the gears is, therefore, a helicoidal motion about the axis 35. The

lead of this motion or advance per revolution can be determined as follows:

L=2rz' tan a=21rz tan a (3) When the axes 31 and 32 are at right angles:

tan a tan a" (3a) A helicoidal member 37, shown diagrammatically in Figures 8 and 9, can'be constructed so that its pitch surface will contact with the pitch surface 33 of .a gear having an axis 31, such as the gear of Figures 6 and7, along the instantaneous axis 35 and so-that at any instant the relative motion between the pitch surface of the helicoidal member 37 and'the pitch surface 33 .of the gear is identical with the relative motion between the pitch surfaces 33 and 34 of the gears shown in Figures 6 and 7. In other words, the relative motion between the helicoidal member 37 and the gear whose pitch vsurface is represented at 33 must be, at any instance, a helicoidal motion about the instantaneous axis 35, with a lead as given by formula (3 3 The structure and position of the helicoidal member 37 can now be determined. Let

D be the lead of the helicoidal member, z the distance of its axis 38 from the instantaneous axis 35, and a the angle between its axis 38 and the instantaneous axis 35,-(see Figs. 8 and 9). With the known methods of kinematics, the following formulas can be derived:

2 will be negative when the axis 38 of the helicoidal member lies between the instantaneous axis 35 and the axis 31 of the gear while formula ('5) remains the same. From these formulas it follows that an infinite number of helicoidal members exist which can mesh with a gear of the type referred to and which possess a relative motion of a type identical to that of the gear. Any one of .thesemembers. may be employe therefore, as a basic member from which the its pitch surface and conjugate,

opposite hands.

other exactly, the teeth of one member fit ting and completelyfilling the tooth spacesgear may be derived. It follows, also, that a gear having a pitch surface33 capable of meshing with a third member 37, with a gear having a pitch surface 34 which itself is capable of meshing with a helicoidal member complementary to the member 37. The teeth of the complementary helicoidal segments are naturally curved in opposite hands, and on one segment will lie. outside on the other segment inside its pitch surface.

The relationship plementar helicoidal segments, to which the two mem ers of a pair of longitudinally curved tooth hypoid gears may be generated is shown diagrammatically in Figure 5.- These segments 39 and 40 have longitudinally curved teeth which are of Their teeth inte'rfit one anof the other member.

The two segments have the same axis 41."

H from the infinite numbers of helicoidal segments which can. mesh with the gear of the type referred to, one is chosen Whose can mesh between the pairof comaxis is at right angles to the instantaneous axis, formulas (4) and (5) become:

4b) and 0 b r L tan a (5 generated conjugate to each other by cutting one gear by effecting a cutting motion tool, as a between a tool and a gear-blank while simultaneously producing a relative motion between the tool and blank as though the blank were meshing with the basic helicoidal segment represented by the tool, and by generating the other gear in a similar manner. conjugate to a helicoidal segment complementary to the segment to which the 'first gear was generated conjugate.

Gears pairs roduced according to this invention will e proportioned preferably according to the principles disclosed in my prior Patent No. 1,622,555, issued March 29, 1927.

Gears may be cut with this invention with a reciprocating tool which is moved in a curved path or witha continuously rotating face mill. The required cutting motion will be imparted to the tool and simultaneously a relative movement will be produced between the tool and blank as though the blank were meshing with the basic segment represented by the tool. This relative movement preferably will consist of a rotation of the blank on its axis, of a relative movement between the tool and blank about the axis of the helicoidal segment, which axis will be angularly disposed to and I offset from the axis ofthe blank and of a with reference general principles employed in cutting spiral p conjugate to one relative feed movement between the tool and blankinthe direction of the axis of the helicoidal segment. The tool may be positioned to the blank according to the longitudinally curved tooth) bevel gears, and gears of any desired spiral angle may be out. One gear of a pair will be generated helicoidal segment and the other member of the pair will be generated conjugate to a helico dal segment complementary to the first. The cutting edges of the-tools may be straight or curved.

' In Figure 10 I have shown a pair of rotary annular face mills 55 and 56 such as might .be employed for producing gears with-this invention conjugate to complemencomplementary basic segment tary basic helicoidal segments. One tool 56 is a male tool representing a tooth surface or tooth surfaces of one segment. The other tool 55 is a. female tool interfitting exactly with the male tool and representing a tooth surface or tooth surfaces of a segment comlementary to the segment whose tooth surace or tooth surfaces are swept out by the tool 56. The axes of the two tools are at 57 and 58, respectively. The line 59 indicates the pitch surfaces of the complementary segments whose axes coincide and are indicated at 60.

The tools 55 and 56 are provided with straight profiles, representing the straight profiled tooth surfaces of complementary basic segments. In Figure 11 a pair of grinding wheels 61 and 62 are shown having grinding surfaces 63 and 64 and 65 and 66, respectively, which are portions of spherical surfaces, representing portions of the side tooth surfaces of basic helicoidal segments Whose tooth surfaces are portions of spherical surfaces of revolution.

Figure 12 shows the relation between one of these tools 62 and the basic helicoidal segment 68 which the tool represents. Adjacenttooth sides of the basic helicoidal seg ment 68 are parts of convex and concave spherical surfaces, respectively, which may have equal sphere radii 69 and 70. Adjacent tooth surfaces have centers 71, 72,73, 74:, 7 5 and 76, etc. located in two helices 78 and 79. The centers of the convex surfaces of the segment 68,- represented b ing wheel 62, are lbcated on t while those of the concave surfaces are located on the helix 79. 1 The two adjacent spherical sides 'of a'tooth of the basic segment may be represented by the wheel 62 when the axis 80 of the wheel 62 is so inclined as to pass through the centers 7 4 and 7 5 of the tooth sides. In a similar manner, the two adjacent spherical tooth sides of the may be represented by the grinding wheel' 61 when its axis 81 is so inclined as to pass through the centers75 and 76 of adjacent tooth sides of the complementary segment. By positioning the tools in the manner described, a (pair of male tools may be em loyed to pro uce conjugate gears, and with such tools it is ossible to produce teeth of tapering depth.

In certain cases,

of structural advantages obtainable in machines employed for practising this invention, a slight departure from theoretical requirements' is possible. So, a pair of basic helicoidal segments may be employed in generating a pair of gears according to this invention which are not exactly mentary, as the segments 83 and 84 shown in Figure 13 and by the face mills 85 and 86. These segments have teeth arranged on helicoidal surfaces the grind e helix 78, 1

complewhich may be'represented for the sake, especially,

not a relative motion as though the blank were meshing with a true crown gear, but a relative motion in which the tool represents a basic gear having a plane top surface and a conical pitch surface. I

One form of machine for practising this invention is shown in Figures 14 and 1.5. In the embodiment illustrated, a rotary annular face mill is employed. This tool may be so constructed that in any one operation it finish cuts one tooth side of the blank only or may be provided with cutting edges adapted to simultaneously finish cut adjacent tooth sides of a blank. The cutting edges of the tool represent tooth surfaces of the basic helicoidal segment to'which the gear to be cut is to be generated conjugate. The tool 90 is journaled in an upright 91 and is adjustable thereon and with reference to the cradle 92 in such manner as to per? mit of it being positioned in proper cutting engagement with the blank, indicated at B.

The cradle 01' carrier 92 upon which the tool is supported is mounted for rotation or oscillation in the frame 93. The axis of the cradle represents the axis of the basic helicoidal segment. The blank is secured to a spindle 94 which is journaled in a slide 95 which can be adjusted vertically on an upright 96 which in turn may be angularly adjusted in any suitable manner upon the table or slide 97. The angular adjustment of the upright '96 permits of bringing the blank into the proper tangential plane for cutting, while the vertical adjustment of the slide 95 permits ofoffsetting the axis of the blank any desired distance from the axis of the cradle, whereby to position the blank axis in the required relation to the axis of the helicoidal segment.

The slide 97 is provided with guide rails 98 which move in guide ways formed in the base 99 secured to or integral with the frame 93. The movement of the slide or carrier 97 is in a direction parallel to the axis of the cradle 92.

During generation, the tool is rotated on its axis in engagement with the blank, the blank spindle rotates on its axis, the cradle 92 rotates on its'axis and simultaneously a feed movement is imparted to the slide 97 toward or away from the cradle, depending on the direction of rotation of the 'blank'and cradle. The rotation of the blank, the rotation of the cradle and the feed of the slide 97 I are all timed together so that the relative movement of tool and blank corresponds to that of a gear meshing with a basic helicoidal segment represented by the tool. Gearmg curvature, representing for imparting to the various parts their required motionis indicated rather diagrammatically in Figures 18 and 19. So the cutter is shown as continuously rotated from the motor 100 through the gears 101 and 102. The cradle 92 -has a Worm wheel segment 104 secured to it and isdriven by the worm 105 V which meshes with this segment. The worm.

is mounted upon a shaft 106 which is driven through the bevel gears 107, the shaft 108, and the bevel gears 109 from the main drive shaft 110, which is drivenby the motor 111 through the bevel gears 112. The shaft carries midway its length a bevel gear 113 which meshes with a bevel gear 114 on a vertical shaft 115. The vertical shaft 115 carries at its upper end a spur gear 116 forming one of a set of change gears which transmit the rotation of the shaft 115 to the worm shaft 117 carrying a worm 118 which meshes with a worm wheel 119 secured to the blank spindle 94. At its outer end the shaft 110 carries a spur gear 120 forming one of a set of chan e gears which transmits the rotation of the s iaft 110 to a feed screw 121- which is mounted in the base 99 and which threads into a nut 122 secured to the slide 97.

In operation the tool rotates in engagement with the blank, while the blank rotates on its axis and while the cradle slowly moves about its axisand the blank slide 97 is given a movement in a direction parallel to the cradle axis. The last three motions are in timed relation and generate the tooth profiles. When the cradle has been so turned that a tooth profile or adjacent tooth profiles are completely generated, the tool and blank will be withdrawn relatively to each other and the blank indexed. The blank will then be returned into engagement with the tool and the cycle will commence anew with the generating operation proceeding upon a new tooth face or tooth faces of the blank. For the sake of clearness, the mechanism for effecting the relative withdrawal and return for indexing and the mechanism for effecting the indexing itself have been omitted. Any

usual or sultable mechanism for these purposes may beemployed, however, as will be readily understood. It will be understood, also, that instead of intermittently indexing the blank, the blank may be continuously indexed, as in a hobbing' operation and the tool, then, will be a hobbing tool, either of the face mill or worm type.

Instead of a continuously rotating tool, it is obvious that a reciprocating tool may be employed instead, the tool being reciprocated in a curved path across the face of the blank.

In any case, however, the points of the cutting edges of the tool will move along lines lying in parallel planes, that is, the cutting Y edges will move along a line of constant a tooth side of the basic helicoidal segment.

ing tapered While I have illustrated one embodiment of a machine for practicing this invention, it will be understood that various other types of machines may be employed, also. In general, the methods employed for the cutting of bevel gears may be applied to the cutting of the hypoid' gears described, when so modified as to allow for the helicoidal nature of the basic segments.

While I have described my invention particularly with reference to hypoid gears havbodies it is obvious, also, thatthe invention relates to other forms of gears with non-intersecting axes, as worm gears.

Gears which are derived from a basic ele ment whose tooth surfaces are surfaces of revolution can readily be ground and the term cutting? as employed in the specification and clains is intended to include the production of gears by a grinding operation also.

In general, it ma have illustrated an described certain preferred embodiments of my invention, it will be understood that the invention is-capable of further modification within its limits and the scope of the appended claims. and that this application is intended to cover any variations, uses, or adaptations of my invention, following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the gear art and as may be applied to the essential features hereinbefore set forth. andas fall within the limits of the appended claims.

Having thus described my invention, what I claim is:

1. The method of producing a gear which consists in cutting its side tooth surfaces by moving a tool in a curved path across the face of a gear blank while simultaneously producing an additional relative movement between the tool and blank corresponding to that of a gear meshing with a helicoidal segment.

2. The method of producing a gear which consists in cutting its side tooth surfaces by moving a tool, in a ,circular arcuate path across the face'of a gear blank while simultaneously producing an additional relative movement between the tool and blank corresponding to that of a gear meshing with a helicoidal segment.

3. The method of consists in cutting its side tooth surfaces by rotating an annular face mill in engagement with a gear blank while simultaneously producing an additional relative movement between the tool and blank correspondingto that of a gear meshing with a helicoidal. seg}' ment. V 4'. The method of producing a gear which. consists in moving a tool in acurved path across the face of a gear blank so that points be said that while I producing a gear which tween the tool and blank corresponding to' that of a gear meshing with a helicoidal segment.

5. consists in cutting its side tooth surfaces by moving a tool in a curved path across the face of a gear blank While rotating the blank on its axis and simultaneously producing an additional relative movement between the tool and blank about an axis angularly disposed to and offset from the blank axis and simultaneously and in timed relation to the two last named movement-s imparting a feed movement between the tool and blank in the direction of the last named axis. p

6. The method of producing a gear-which consists in cutting its side tooth surfaces by moving a tool in a curved path across the face of a gear blank while rotating the blank on its axis and simultaneously producing a relative movement between the tool and blank about an axis offset from the The method of producing a gear which blank axis and simultaneously and in timed relation to the two last named movements imparting a relative feed movement between the tool and blank at an angle to the blank axis.

7. The method of producing a gear which consists in cutting its side tooth surfaces-by moving a tool in a circular arcuate path across the face of a gear blank, while rotat- Hill in the blank on its axis, simultaneously 1 b I n 4 I producing an additional relative movement between the tool and blank about an axis angularly disposed-to and ofiset from the blank axis and simultaneously and in timed relation to the two last named movements imparting a feed movement between the tool and axis.- v 8. The method of producing a gear which consists in cutting its side tooth surfaces by,

rotating an annular face mill in engagement with a gear blank, while rotating the blank on its axis, simultaneously producing an" additional relative movement between the tool and blank about an axis singularly disposed to and offset from the blank axis and simultaneously and in timed relation to-the two las named movements imparting a feed.

movement between the tool and. blank in direction of the last named axis. 9. The method of producing a gear hich blankin the direction of the last named I consists in cutting its side -tooth surfacesby moving. a tool .in a curved path across. the face 'ofia gear cuttin I edge move along lines lying ingpar le i p a e whi ro at ng' e h en jlbn t v.

axis, simultaneously producing jan atldiblank. so that points of its'l' tional 3 relative movement between the' tool.

and ,blank about:anI axis angularly.

to and offset from the blank axis and simultaneously and in timed relation to the two 'last named movements imparting a feed movement between the tool and blank in the direction of the last namedaxis.

10. The method of producing a pair of gears which are adapted to mesh with axes non-intersecting, and non-parallel, which basic helicoidal segment provided with teeth whose sides are surfaces of revolution, and in generating the side tooth surfaces of the other member of the pair conjugateto a basic helicoidal segment complementary to the first segment.

12. The method of producing a pair of gears which are adapted to mesh with axes non-intersecting and nonsparallel, which consists in generating the side tooth surfaces of one member of the pair conjugate to a basic helicoidal segment having longitudinally curved teeth whose side tooth surfaces are of constant profile and such as might be generated by a line, the points of which move in parallel lanes, and in generating the side tooth sur aces of the other member of the pair'conjuga'te to a basic helicoidal segment complementaryto the first segment.

13. In a machine for producing gears, a blank support, a tool, means for adjusting the tool and blank support into cutting en-.

gagement, means for moving the tool .in a-' curved pathacross the face of the blank and means for simultaneously imparting an additional relative movement between the tool and blank corresponding to that'of a gear meshing with a helicoidal segment.

14. In a machine forproducing gears, a blank support, a tool, means the tool and blank supports into cutting in a circular arcuate path across the face gear blank, and means for simultaneously imparting an additional relative movement between the'tool and blank corresponding to that of a gear meshing with a basic helicoidal segment,

15. In a machine for producing gears, a blank support, a tool, means for adjusting the tool and blank support into cutting relation means for moving thegtool in a curved path across the face of a gear blank so that points in its cutting edge move along lines lying in parallel planes, and means for si for adjusting:

of a

' to and offset from the multaneously imparting an additional relative movement between the tool and blank corresponding to that of a gear meshingwith a helicoidal segment. i

16. In a machine for producing gears, a blank support, a tool support, a rotary an nular face mill journaled in said tool support, means for adjusting the tool and blank supports. into cutting relation, means for rotating the face mill on its axis in engagement with the blank, and means for simultaneously imparting an additional relative movement between the tool and blank corresponding to that of a. gear meshing with a basic helicoidal segment.

17. In a machine for producing gears, a blank support, a tool, means for adjusting the tool and blank support into cutting relal tion, means for moving the tool in a curved path across the face of a gear blank, means for rotating the blank on its axis while in engagement with the tool, means for simultaneously imparting an additional relative movement between the tool and blank about an axis angularly disposed to and offset from the blank axis, and means for: simultaneously and in timed relation to the two last named movements producing a relative feeding movement between the tool and blank in the direction of the last named axis.

18.'In a machine for producing gears, a

blank support, a tool, means for adjusting the blank support and tool into cutting relation, means for moving the tool in a circular arcuate path across the face of a gear blank, means for rotating the blankon its axis while: in engagement with the tool,

means for simultaneuosly imparting an additional relative movement between the tool and blank about an axis angular-1y disposed to and offset from the blank axis, and means .for simultaneously and in timed relation to the two last named movements producing a relative feed movement between the tool and blank in the direction of the axis about which the last named movement takes place.

19. In a machine for producing gears, a

blank support, a tool support, a rotary annular face mill journaled in said tool sup: port, means for adjusting the tool and blank supports into cutting relation, means for rotating the tool in engagement with the blank, axis while in engagement with the tool, means for simultaneously imparting an additional relative movement between the tool and blank about an axis angularly disposed blank-axis and means for simultaneously andin timed relation to the two last named movements producing a relative feed-movement between the tool and blank in the direction of the axis about which thelast named movement takes place.

-20.' In amachine for tool support, a tool movably mounted theremeans for rotating the blank on its producing. gears, a

on, a blank support, a rotatable blank spindle journaled therein, a frame, a carrier, upon which one of said supports is mounted, journaled in said frame, means for positioning the blank support with its axis offset from the axis of said carrier, means for adjusting the tool and blank into cutting relation, means for moving the tool in a curved path across the face of the blank, means for simultaneously rotating the blank spindle on its axis, means for simultaneously moving the carrier about its axis and means for simultaneously and 1n timed relation to the two last named movements imparting a feed movement between the tool and blank in Y the direction of the last named axis.

' 21. In a machine forproducing gears, a tool support, a tool movably mounted theredle journaled therein, a frame, a carrier, upon which one of sald supports 1s mount ed, 1ournaled in said frame,

from the axis of said carrier, means for ad justing the tool and blank into cutting re lation, means for moving the tool in a circular arcuate path across the face of a gear blank, means the blank spindle on its axis, means for simultaneously moving the carrier about its axis, and means for simultaneously and in timed relation to the two last named move ments imparting a feed movement between the tool and blank in the direction of the last named axis. 22. In a machine for producing gears, a tool support, a rotary annular face mill journaled therein,-.a blank support, a rotatable blank spindle journaled therein, a frame, a carrier, upon which one of said supports is mounted, journaled in said frame, means for positioning the blank spindle with its axis offset from the axis of said carrier, means for adjusting the tool and blank into cutting relation, means for rotating the tool in engagement with the blank, means for simultaneously rotating the blank spindle on for simultaneously moving its axis, means and means for the carrier about its axis,

simultaneously and in timed relation to the two last named movements imparting a feed movement between the tool and blank in the direction of the last named axis.

23. Ina machine for producing gears, a tool support, a tool movably mounted thereon, a blank support, a rotatable blank spin a blank support, a rotatable blank spinmeans 1 for positioning the blank spindle with its axis offset for simultaneously rotatingdle journaled therein, a frame, upon which one of sald supports is mounted, journale-d in said frame, a slide upon which the other of said supports is mounted, slidable on said frame in a direction parallel to the axis of said carrier, means for positioning the blank spindle with its axis offset from the axis of said carrier, means for adjusting the tool and blank into cutting relation,'means for moving the tool in a curved path across the face of the blank,

and means for simultaneously rotating the said carrier, means for adjusting the tool offset from the axis ofa carrier,

and blank into cutting position, means for moving the tool in a circular arcuate path across the face of the blank, means for simultaneously rotating the blank spindle on its axis, means for simultaneously moving the carrier about its axis, and means for simultaneously and in timed relation to the two last named movements imparting movementto said slide.

25. In a machine for producing gears, a tool support, a rotary annul"r' face mill journaled therein, a blank support, a. blank spindle journaled therein, a frame, a carrier, upon which one of said supports is mounted, iournaled in said frame, a slide, upon which the other of said supports is mounted, slidable on said frame in a direction parallel to the axis of said carrier, means 'for positioning the blank spindle with its axis ofiset from the axis of said carrier, means for adjusting the tool and blank into cutting relation, means for rotating the tool in engagement with the blank, means for simultaneously rotating the blank spindle on its axis, means for simultaneously moving the carrier on its axis, and means for simultaneously and 1n tlmed relation to the two last named movements lmparting movement to said slide.

ERNEST WILDHABER. 

